Melasma and the sun: why dark patches come back and how to protect your skin
Melasma is a common skin condition that causes tan, brown or gray-brown patches, usually on the cheeks, forehead, chin or above the upper lip. It isn't dangerous or contagious, but it can be stubborn, and sun exposure is the main thing that makes it darker or brings it back.
- Melasma is most common in women, especially those with medium to dark skin tones, and often starts during pregnancy or with birth control pills.
- Sunlight makes skin produce more pigment, darkening patches and causing new ones.
- Dermatologists often recommend daily SPF 30+ broad-spectrum sunscreen with zinc oxide, titanium dioxide or iron oxide (tinted).
Who gets melasma
The American Academy of Dermatology: Melasma overview page says melasma is most common in women, and that women with medium to dark skin tones are most likely to develop it. Many first notice it during pregnancy (it's sometimes called the "mask of pregnancy") or after starting birth control pills, and for some it fades after the baby is born or after stopping the pill.
Why the sun matters so much
In its American Academy of Dermatology: Melasma diagnosis and treatment guide, the AAD explains that sunlight causes the skin to make more pigment, which can darken existing melasma and cause new patches. That's why melasma often looks worse in summer, and why it commonly returns after treatment if sun protection slips. The AAD says it's common for melasma to return when you spend time in the sun.
This is also why tanning is a poor fit for anyone with melasma: deliberately darkening skin with UV works against every treatment (see tanning beds and UV risk and the base tan myth).
Sun protection dermatologists recommend
- A wide-brimmed hat outdoors, and shade when you can.
- Broad-spectrum sunscreen, SPF 30 or higher, applied throughout the day.
- Sunscreen containing zinc oxide, titanium dioxide or iron oxide. If mineral sunscreen leaves a white cast, the AAD suggests a tinted sunscreen; iron oxide is what gives tinted formulas their color.
Treatment basics
A dermatologist may prescribe hydroquinone, tretinoin, a "triple combination" cream (tretinoin, a corticosteroid and hydroquinone), or gentler options like azelaic acid. For stubborn cases, tranexamic acid (usually a pill) may be added; the AAD notes your dermatologist will ask about your health first, especially any history of blood clots. Results usually take 3 to 12 months.
A few cautions from the AAD:
- If you're pregnant, wait until after the baby is born to treat melasma; it may fade on its own.
- Use a non-prescription melasma product for no longer than three to six months; if it isn't working, see a dermatologist.
- Treatment can fade melasma but can't cure it, so daily sun protection is part of keeping results.
If a dark spot is changing, has irregular borders or looks different from your other spots, get it checked; see the ABCDE mole check.
Educational information only, not medical advice. See a board-certified dermatologist for diagnosis and treatment. See our medical disclaimer.
Published October 28, 2026. Sources are linked in the text. See our Medical Disclaimer.